package test1;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Leetcode2 {

}


class Solution2 {
    public List<List<Integer>> threeSum(int[] nums) {
        int n=nums.length;
        Arrays.sort(nums);
        List<List<Integer>> ret=new ArrayList<>();
        for(int i=0;i<n;){
            int left=i+1;
            int right=n-1;
            int tem=-nums[i];
            if(nums[i]>0)break;
            while(left<right){
                int sum=nums[left]+nums[right];
                if(sum>tem)right--;
                else if(sum<tem)left++;
                else{//相等
                    ret.add(new ArrayList<Integer>(Arrays.asList(nums[i], nums[left], nums[right])));
                    left++;
                    right--;//去重
                    while(left<right&&nums[left]==nums[left-1])left++;
                    while(left<right&&nums[right]==nums[right+1])right--;
                }
            }
            i++;
            while(i<n&&nums[i]==nums[i-1])i++;
        }

        return ret;

    }
}
